Box nailing machine



4 Sheets-Sheet 1 IN VENTOR.

ArraeA/Ey.

a a a G. c. CABLE BOX NAILING MACHINE May 26, 1953 Filed Sept. 8, 1951 May 26, 1953 G. c. CABLE BOX NAILING MACHINE Filed Sept. 8, 1951 4 Sheets-Sheet 2 INVENTOR. Gav V52 C 6,481.5,

BY Z

- ArraeA EY.

' I'//III/IIIIIIIIIIA Y 6, 1953 5. c. CABLE 2,639,427

BOX NAILING MACHINE Filed Sept. 8, 1951 4 Sheets-Sheet 3 y 6, 1953 G. c. CABLE BOX NAILING MACHINE Filed Sept. 8, 1951 4 Sheets-Sheet 4 m M C a e M e 6 IN VEN TOR.

ATTORNEY- I Patented May 26, 1953 UNITED STATES PATENT OFFICE BOX NAILING MACHINE Grover C. Cable, Huntington Park, Calif. Application September 8, 1951, Serial No. 245,694

My invention relates to box nailing machinery, and more particularly, to an improvement therein for accurately registering work pieces to be nailed together in proper nailing position. Though my invention may also be applied to the manufacture of boxes, and to the manufacture of laminated panels, and to the lidding of boxes, it is described herein with particular reference to the manufacture of pallets.

Pallets of the type with reference to which my 15 Claims.

. cation when read in connection with the accominvention is particularly described herein comprise a plurality of joints to which a plurality of interconecting cross-boards are nailed. Such a pallet is employed to form a side, or the floor, of a box or crate.

In the use of box nailing machinery in the manufacture of such pallets, the joists and the cross-boards are usually assembled in intersecting relationship in a jig, and the jig is advanced along a track to a position where the joists and cross-boards to be nailed together register in nailing position with box nailing members which are employed to punch the nails into the intersecting portions of the joists and cross-boards. For convenience herein the joists and crossboards are sometimes referred to more broadly as work pieces to emphasize the fact that the use of my invention is not limited to the manufacture of pallets.

In practice, it is found that the registering of the intersecting work-pieces in nailing position consumes considerable time, it being common to move the jig back and forth along the track in an attempt to adjust it to registering position by eye. This time-consuming element of the nailing operation is eliminated in accordance with my invention by means of a simple, low-cost, reliable, automatic registering mechanism in the form of accessories that may be readily attached to present box nailing machines.

An object of my invention is to provide an improved nailing machine in which a pair of superposed work pieces are automatically and accurately registered in nailing position when advanced along a track.

Another object of my invention is to provide a nailing machine with a stop which automatically registers superposed work pieces in proper nailing position with means for withdrawing this stop after the nailing operation and for cocking a trigger that returns the stop to operating position when another pair of superposed work pieces is advanced toward nailing position.

Another object of my invention is to provide an improved means for operating and withdrawing a registering stop from a track alongwhich panying drawings, in which:

Figure 1 is a front elevational view of a nailing machine incorporating registering accessories in accordance with my invention;

Fig. 2 is a fragmentary sectional view showing a portion of those accessories taken on the line 22 of Fig. 1;

Fig. 3 is a fragmentary isometric view showing details of the registering mechanism with the nailing members in raised position;

Fig. 4 is a fragmentary sectional view taken on the line 2-2 of Fig. 1 showing the nailing members in lowered position after completion of a nailing operation;

Fig. 5 is a fragmentary sectional view illustrating the action of the cam bar taken on the line 55 of Fig. 3.

Fig. 6 is a fragmentary sectional view of the detent lock taken on the line 6-43 of Fig. 3;

Figs. 7-8 are fragmentary sectional views taken on the line 11'of Fig. 3 illustrating. the operation of the registering mechanism as a pallet is advanced along the track to nailing position;

Fig. 9 is a fragmentary detailed plan view of an alternative form of stop;

Fig. 10 is a sectional View of the alternative form of stop taken on the line IEJHJ of Fig.8;

Fig. 11 is a fragmentary plan view of an alternative form of stop release mechanism;

Fig. 12 is a fragmentary sectional view of the alternate stop release mechanism taken on the line l2l2 of Fig. 10;

Fig. 13 is a perspective view of a jig employed in making pallets in accordance with my invention; and

Fig. 14 shows the jig with the pallet in place after nailing.

Referring to the drawings, and particularly to Fig. 1, there is illustrated a nailing machine of the type to which my invention has been applied, only so much of the nailing machine being illustrated and described as is necessary to an understanding of my invention. This particular nailing machine is commonly employed for making boxes, pallets and laminated panels, and also for lidding boxes and for other purposes.

The nailing machine comprises a pair of upright members 20 between which a horizontal track 22 is mounted. The bed 26 of the track 22 is secured to the upper side of a cross-bar 24 and is also supported by other means (not shown) so as to maintain the bed horizontal. The track 22 also comprises a pair of parallel rails or guides 28 in the form of angle bars having their horizontal sections 23 secured by bolts 39 to the bed 2! with their vertical sections 3| extending upwardly from the bed .22. The angle bars 23 extend horizontally perpendicular to the plane of the uprights 3% and are adjustably positioned upon the bed 255 to accommodate work of different widths. The vertical sections 3! act as guide bars to feed work accurately into position.

A jig ll! is usually employed in making a pallet with this nailing machine, the design of the-jig depending upon the size andltypeof -pallett o be made. In the particular form of jig at illustrated in Fig. 13 three base boards 42 are interconnected by two pairs or cross-bars l t, t and 4t, 4?, at opposite ends thereof, thejig being of rectangular configuration. In order to assure accurate guiding of the jig along thetraclz 22, the outer edges Q5 of the outer base boards 4-2 are spaced apart a distance just slightly lessthan the spacing between the guide bars 31. However, for reasons which will become. apparent hereinafter, the cross-bars 4 3', 45, 4'6 and ll are of a length less than the distance between the guide bars 3| and the outer ends of these crossbars are spaced inwardly from the outer edges 43 of the jig 6. The outer cross-bars 44 and 46 are of less height than the inner cross bars 35 and 4?, and the inner cross-bars 45 and-,4? are provided with staples 58 to aid in assembling crosspieces from which a pallet is to be made.

In making a pallet, airont joist. 52 is placed between the front pair of cross-bars Mend these cross-bar's being spaced apart a distance just suihcient to accommodatethe front joist readily. Similarly, a rear joist 5. 1 is placed between the rear pair of cross-bars. db and 41, these cross-bars also being spaced apart a distance just sufficient to accommodatetherear joist readily. Both joists 52 andsi ar'e longerthan the crossbars 44, 45, do and 51, each having a length equal to the'width of the jig 4'9. The ends of the joists are aligned. with the edges as of the jig at. A plurality of frontor side boards 58 are then laid in predetermined positions upon the joists extending perpendicular thereto in intersecting relationship therewith, the positions of the boards efi'being established by the staples 56.

To nail the joists 52 and 54' and the boards 58 together to complete the pallet, the jig 6% is advanced from the rear of the nailing machine to the front in the direction indicated; by the arrow (ill in Figs. 7 and 8, with thejoists Stand 54 perpendicular to the axis of the track and the boards 58 parallel to the axis of the track.

Two stops G2 in the form of cylindrical pins are movable laterally through openings 84in the guide bars 35 between inner, or operative, positions, as indicated in Fig. 8 and outer, or inoperative, positions, as indicated in Fig. 7. When the stops 62 are in their inner, or operative, positions, they are in position to engage'thefront faces of the joist 52 or 54 to limit the advancement of the jig 40 along the track and to halt the joist so engaged in nailing position just behind the stops 62. But when thestops' weave been withdrawn to their outer, or inoperative positions, the joists may be advanced past the na'il'ingposition. The remainder of the registering mechanism, which is employed to automatically move the stops inwardly and outwardly of thetra'ckbetvv'eentheir operated and withdrawn positions, are described in detail hereinafter.

The nailing of the work pieces, that is joists 52 and 54 and cross-boards 58, with the machine here illustrated is accomplished by means of a pair of horizontal nailing members and E38 mounted on the uprights 2E3 for vertical reciprocation relative to the track 2 2 the nailing members being successively lowered by mechanical rheans '(not'shown) to force nails into the intersecting work pieces. More particularly, the lowor nailing member, or chuck-supporting bar, 65 carriesa plurality of nail chucks Iii which are individually supplied nails from a nail pan H through hell tubes 72. The chucks it are adjustable forw ardly and rearwardly in a horizontal line transverse of the chuck-supporting bar 66in order that the nails may be nailed into the joists either along a straight line or in staggered relation as desired. The upper nailing member or nailing bar 58 carries a plurality of nailing rods M which are adapted for reciprocation in channels (not shown) the chucks t to force nails out of the bottoms of the chucks.

In the Operation of the nailing machine, when it is desired to nail cross-boardsto a joist which hasbeen placed in nailing position, a foot; clutch pedal (not shown) is pressedputtinginto operation a mechanism which lowers the chuck-suppcrting bar 69 to bring the chuck-s- '56 into contact with the upper surfaces of the boards .58 and also lowers the nail-driving bar G8 while the chucks are in such contact to force the nailing rods i l downwardly, pressing thenails through the boards 58 into theparticular joist or 54 that is in nailing position. The two nailing members Gil and 6% then return automatically to their normal elevated positions quickly, and nails are fed through the tubes it! into the chucks is preparatory forthe next nailing operation.

In accordance with my invention thestops or registering pins 62 normally project inwardly of the guide bars 3!, indicated in- Fig. 8, being secured to the rear ends of'flat leaf springs '55 that are secured at their front ends to the guide bars. The front ends of the leaf springs 76 are attached to the guide bars 3 i. by'means of screws l8 and the stops 62 are provided with reduced threaded portions '82 at their outer ends which reduced portions project through the leaf springs to engage lock nuts 84 for securing the stops in place on the leaf springs 16. The leaf springs l6 lie in vertical'planes normally urging the stops 62' into their inner or operative'positions and normally lying adjacent to though spaced slightly from the vertical guide plates 31. The rear ends of the leaf springs 16 are bent outwardly at right angles to form short outwardly extending arms 35 that serve as clocking members as explained hereinafter.

According to my invention a pair oilocl'ring'devices are provided for locking'the steps 52 in their outer or withdrawnpositions as'illus'trated' in Fig. 7 to permit a joist 52 orfl'to be advanced forwardly along the track 22 after the boards 58 have been hailed theretoas' indicated'iiiFig's. 3, 6, 7 and 8. Each locking device'comprise's a'latching bar or bolt 86 adapted for sliding forwardly and rearwardly'betweena pair or'st'aucn'ar bars or "guides 88 fastened between a cover plate 5! and a support or base plate 92 attached to each of the track bars 3| at a 'position'behind the stops 62. The rear portion of each latching b'ar'BG is reces'se'd'to form a forwardlyiaeihg shoulder '94 engageable' with a trlggerliireniberor lever"9'6 (see Figs. '7 and 8) that is pivotally supported by a vertical pin 98 (Fig. 3) mounted transversely of a window I in each support plate 92. An aperture I02 formed in each track bar 3| in registry with the corresponding window I00 permits the inner arm or end I04 of each lever 96 to be moved into and out of the track 22 whilethe outer arm or end I06 abuts the shoulder 94 of the latching bar 86.

Each locking device also comprises a locking spring I08 that serves to urge the latching bar forwardly into locking position, the spring I08 being connected between the outer end of the corresponding blocking member 85 and a pin I I0 projecting outwardly fromthe rear end of the corresponding latching bar 86. While the stops 62 are in their inner or operative positions (Fig. 8), the forward movement of each latching bar 86 is limited by the abutment of its forward end against the blocking member 85, but when the stops 62 are withdrawn to their outer inoperative positions (Fig. 7), each of the springs I 08 forces the corresponding latching bar 86 forwardly into a position between the rear end of the corresponding leaf spring I6 and the adjacent guide bar 3| to retain the stop in its outer, or inoperative, position (Fig. 7). At the same time, the shoulder 94 at the rear of the latching bar 86 forces the outer end of the corresponding lever 96 forwardly, rotating the lever to force the inner end thereof inwardly of the track into a position where it may be tripped by a joist 52 or 54 that is advanced'forwardly past the lever. Each of the levers 96 is retained in its operative position by engagement with the rear end III of the aperture I02 as clearly shown in Fig. '7.

Also, in accordance with my invention, suitable means are provided for simultaneously forcing the two leaf springs I6 outwardly in the course of the nailing operation. In the particular form of the invention illustrated in Figs. 1 to 8, inclusive, this means comprises a pair of cam bars II2, each of which has a horizontal arm II4 securely attached to the nailing bar 66 and a vertical arm II6 that extends downwardly toward the track. The inner surfaces of the vertical arm II6 are fiat and the outer surfaces thereof are inclined inwardly and downwardly forming tapered edges at the lower extremeties thereof that lie between the corresponding guide bars 3I and leaf springs I6. With this arrangement, leaf springs I6 are forced outwardly as the nailing bar 66 is lowered during the nailing operation.

In operating the nailing machine in accordance with my invention, the automatic registering mechanism may be prepared for operation initially by drawing the leaf springs I6 outwardly thus permitting the locking springs I08 to force the latching bars 86 forwardly into positions where they retain the stops 62 in their outer, or inoperative,.positions and to rotate the inner ends I04 of the levers 96 into the working space of the track 22 between the rails 28 as shown in Figure 7. Thereafter, when the joists 52 and 54 and the boards 58 to be nailed together are assembled in the jig 40, the jig is pushed forwardly on the track from a position starting behind the levers 96.

When the front joist 52 engages the inner ends I04 of the levers 96, these ends are pressed forwardly, rotating the levers to withdraw the latching bars 86 rearwardly, permitting the leaf springs I6 to force the stops 62 into their inner, or operative, positions. As the jig 40 is advanced further, the ends of the leading joist 52 finally engages thestops 62, halting the movement of the jig and registering the joists and the boards in nailing position. directly beneath the nailin members 66 and 6B.

While in that position, the nailing machine is operated, thetwo nailing members 66 and 68 being successively'lowered in the manner hereinabove described, forcing nails through the boards 58 into the front joist 52. Simultaneously, the cam bars II2 are lowered, pressing the leaf springs I6 outwardly, withdrawing the stops 62 to their outer, or inoperative positions. At the same time, the latching bars .66 move forwardly to engage the leaf springs to retain them in their outer positions and to rotate the levers 96 to their initial, oroperative, positions, preparatory to registering the ends of the rear joist 54 in nailing position. After the boards 56 have been nailed to the front joist, the jig is advanced forwardly and the registering mechanism operates again in the manner described above, the levers 96 being rotated this time by the rear joist 54 to cause the stops 62 to be returned to-their operative positions where they register the rear joist in nailing position as the jig advances on track 22. When the boards 58 are nailed to the rear joist 54, the stops 62 are again withdrawn (see Fig. '7) and the levers are again returned to their operative positions by'the action of the cam bars II2, preparatory to registering another set of cross pieces in nailing position when another jig is advanced 'on track 22' as shown by thearrow 60 (Fig. 7).

In an alternate embodiment of my invention, employing a different means for preparing the registering mechanism for operation as illustrated in Figs. 11 and 12, bell cranks I20 are pivotally secured to the uprights 20 for move-' ment about a horizontal axis parallel to the track 22; The upper arm I22 of each bell crank I20 projects inwardly toward the track 22 into a position to be engaged directly by the outer end of the nailing bar 66 as it is lowered. The lower arm I24 of the bell crank I20 extends downwardly and its lower end is connected to the outer end of .the corresponding leaf spring I6, through'the medium of an adjustable linkage I26, comprising threaded rods I28 and I30, interconnected by a turnbuckle I32. The outer rod I28 is provided with a transverse finger I29 that is journalled to the lower end of the vertical arm I24. The inner rod I30 threadably engages an anchor bat I34 fastened to the free end of the lever I6. With this arrangement, when the nailing operation occurs, the nailing bar 66 presses down upon the upper arm I22 of each bell crank I20 as the nailing bar is lowered, rotating the lower arm I24 outwardly, thus withdrawing the stops 62 to their outer, inoperative, positions, where they are locked by the latching bars 86 in the manner hereinabove explained. This form of my invention has the advantage that it is readily adapted to the adjustment of the spacing between the guide bars 28 without requiring a shifting of a cam bar on the nailing bar, the adjustment being readily accomplished, for example, by substituting threaded arms I30 of suitable length between the turnbuckle and the leaf springs.

In order to adapt my registering mechanism to the accurate registration of joists of different predetermined widths in nailing position, I have provided an alternative form of stop member I40, as illustrated in Figs. 9 and 10. This stop memher is in the form of a rectangular block, hav-L i ing "a threaded connector I42, projecting from onefa'ce thereof, the'connector being ofiset from the'center' of the block. One such block I40 is employed in place of each stop pin 62 of the registering mechanism previously described. By rotating these blocks to various positions and securingrthemin place bymeans of nuts 3, the

respective faces [44, I46, I48 and I50 of theblocks may be positioned for engagement by a joist, thus establishing different stop positions for the joists. By suitable dimensioning of the block and suitable spacing of the connector from the axis thereof,- joists of predetermined dimensions may always be stopped, if desired, with their center lines in the same position relative to the nailing members 66 and 68.

From the foregoing description of my invention, it is apparent that I have provided a simple, 'l'ow cost registering mechanism for use in a nailing machine that is positive and reliable in operation and that increases the production ca p'acity of the nailing machine. While my invention has been described with particular reference toits employment with aspecific form of pallet in which the joists'engage the stops, it is 'to be understood that the joists may be registered in nailing position in other ways, if desired, such as by "arranging for members of the jig itself to engage the stops. Likewise, while my invention has been described with particular reference to the manufacture of pallets in which floor boards are nailed to joists, it is to be understood that it also may be applied to the nailing together of other work :pieces. "Furthermore while my invention'has been described with reference to the employment of two simultaneously operating stops, Tit will be clear "that only one step may be used while still retaining many of the advan-'- tages "of myinvention. It is thus apparent "that although my invention has been describedonly with reference to "particular forms and applications thereof/my invention is 'not'limited there to but iscap'able of a wide variety of mechanical embodiments and applications. It is therefore to beun'derstood that various'changes'which wiil now suggest themselves to those skilled in the art maybe made in the material, form, details of construction and arrangement of the elements thereof without departing from "the prih'cipis'crmy iiivention; I therefore do not intend to tie limited'to'the specific embodiments of invention "illustrated amifdescribed herein, but only'by the appendedblaims.

m a nailing machine in which a 'pair'oi work eces are advanced along 'a track to a nailing' 'pos'iito'n in which a nailing member is'lo'w-- cred relative to said'track to nail the two work p'i'e'bes together, the combination therewith of: a stop movable relative to said track between operative and"withdrawn positions, the advancement of said work pieces along said track being limited" by said step when inoperative positionto register said work pieces in nailing-position relati ve't'o said nailing member, means controlled by advancement of 'said'work' pieces toward nailing position while saidstop is in a -withdravl n position formovingfsaid step into operativeposition, and means for withdrawing said stop from operative position to permit saidpiecesto be advanced beyond'said hailingpo'sition.

2. In a nailing machine in which a pair of work pieces are advanced along a track to a nailing position in which a nailing member-is lowered relative to saidtrack to nail the two work pieces 1 in nailing position relative to said together, the combination therewith of: a stop movable relative to said track between operative and withdrawn positions, the advancement of said work pieces along said track being limited by saidstop' when in operative position to register said work pieces in nailing position relative to said nailing member, means controlled by advancen-ient of said work pieces toward nailing position while said stop is in a withdrawn position for moving said stop into operative position, and means controlled by downward movement of said nailing member for withdrawing said stop from operative position to permit said pieces to be advanced beyond said nailing position.

3. In a nailing machine in which a pair of work pieces'areadvanced along a track to a nailing'positioni'n which a nailing member is'lowe'red relative to said track to nail the two workpieces together, the combination therewith of 'a stop movable relative to said track between operative and withdrawn positions, the advancement or Said Work pieces said track being limited by Said stop when in operative position to regist'er said work pieces in nailin position relative to said nailing member, means normally urging said stop into operative position, a locking-member movable between operative and withdrawn positions and operative in said operative position to retain saidsto'p in withdrawn position, a trigger member positioned on said track ahead of said nailing-positionand movable into and out of acocked position, said trigger member when in cocked position being operated by advancemerit of said workpieces along said track past said trigger member toward said nailing position to withdrawsaidlocking member-from its operative position thereby permitting said s'topto move into its operative position, means controlled by downward movement ofsaid'nailing member for withdrawing said stop from its operative position whereby said work pieces may be advanced beyond said nailin position after being nailed together, and means also controlled by downward movement of said nailing member for movmg said locking memberinto its operative positicn and said trigger member into its cocked position.

4. Ina nailing machine in which a pair of Work pieces-are advanced along a trackto a nailing position'i'n which a nailing memberis lowered relative t'o'said track to nail the two work pieces togethen'th'e combination't'hrewith of: a guide bar on said track, a leaf spring secured to said guide bar, a stop attached to the free end of said leaf spring and movable through an opening in guide bar between operative and withdrawn pos1tions,the advancement of said work pieces along said track being limited by said stop when in operative position to'register said work pieces i V I nailing member, a locking member movable between operative and withdrawn positions and operative in said operative position to retain said stop in with- QraWll position, said leaf spring holding said stop "in operative position when said locking member is in withdrawn position, a second spring urg ng said locking member into its operative pos tion, a blocking element attached to said leaf spring and positioned thereon to limit the movement of said locking member in a direction toward ltS operative position when said stop is in its operative position, a "trigger member posit oned on-said' track ahead of said nailing posit on and movable into and out or ac'ocked posit1on;sa1d trigger memberwhen inco'cked position being operated by advancement of said work pieces along said track past said trigger member toward said nailing position to withdraw said locking member from its operative position whereby said leaf spring moves said stop into operative position, and means controlled by downward movement of said nailing member for withdrawing said stop from its operative position whereby said locking member is moved into its operative position and said trigger member is moved into its cocked position and said work pieces may be advanced along said track beyond said nailing position after being nailed together.-

5. In a nailing machine in which a pair of work piecesare advanced along a track to a nailing position in which a nailing member is lowered relative to said track to nail the two work pieces together, the combination therewith of: a guide bar on said track, a leaf spring secured to said guide bar, the free end of said leaf spring being adjacent said nailing position and the secured end thereof being forwardly of said nailing position, a stop attached to the free end of said leaf spring and being horizontally movable through an opening in said guide bar between operative and withdrawn positions, the advancement of said work pieces along said track being limited by said stop when in operative position to register said work pieces in nailing position relative to said nailing member, a locking member movable between operative and withdrawn positions and operative in said operative position to retain said stop in withdrawn position, the rear portion of said locking member being provided with a forward facing shoulder, said leaf spring holding said stop in operative position when said locking member is in withdrawn position, a second spring urging said locking member into its operative position, a blocking element attached to said leaf spring and positioned thereon to limit the move ment of said locking member in a direction toward its operative position when said stop is in its operative position, a trigger lever pivotably mounted for movement about a vertical axis, the outer end thereof being positioned for engagement by said shoulder to permit movement of the inner end thereof into and out of a cooked position, said trigger lever when in cocked position being rotated by advancement of said work pieces along said track past said trigger lever toward said nailing position to withdraw said locking member from its operative position whereby said leaf spring moves said stop into operative position, and means controlled by downward movement of said nailing member for withdrawing said stop from its operative position whereby said locking member is moved into its operative position by the action of said second, sprin and said trigger lever is moved into'its cocked position by the action of said shoulder and tween operative and withdrawn positions, the

advancement of such work pieces along said track being limited by said stop when inoperative position to register said work pieces in nailing position relative to said nailing member, a looking member movable between operative and withdrawn positions and operative in said operative position to retain said stop in withdrawn po-v sition, said leaf spring holding said stop in operative position when said locking member is in withdrawn position, a second spring urging said locking member into its operative position, a'

blocking element attached to said leaf spring and positioned thereon to limit the movement of said locking member in a direction toward its operative position when said stop is in its operative position, and a trigger member engageable by said locking member and positioned on said track ahead of said nailing position and movable into and out of a cooked position, said trigger member when in cocked position'being operated by advancement of such work pieces along said track past said trigger member toward said nailing position to withdraw said locking member from its operative position whereby said leaf spring moves said stop into operative position.

'7. In a nailing machine in which a pair of work pieces are advanced along a track to a nailing position in which a nailing member is lowered relative to said track to nail the two work pieces together, the combination therewith of: a guide bar on said track, a leaf spring secured to said guide bar, a stop attached to the free end of said leaf spring and laterally movable through an opening in said guide bar between operative and withdrawn positions, the advancement of said work pieces along said track being limited by said stop when in operative position to register said work pieces in nailing position relative to said nailing member, said leaf spring holding said stop in operative position when said locking member is in withdrawn position, a locking member movable between operative and withdrawn positions and operative in said operative position to retain said stop in withdrawn position, a second spring urging said locking member into its operative position, a blocking element attached to said leaf spring and positioned thereon to limit the movement of said locking member in a direction toward its operative position when said stop is in its operative position, and means controlled by downward movement of said nailing member for withdrawing said stop from its operative position whereby said locking member is moved into its operative position thereby looking said stop in its withdrawn position so that said work pieces may be advanced along said track beyond said nailing position after being nailed together.

8. In a machine for registering a pair of work pieces as they are advanced along a track to a nailing position in which a nailing member is lowered relative to said track to nail the two sition to register said work pieces in nailing position relative to said nailing member, a support'member secured to said track, a locking rnember slidablymovable on said support member between operative and withdrawn positions and operative in said operative position to retain said stop in withdrawn position, means for urging said locking member into its operative position, a blocking element for limiting the movement of said locking member when said stop is in operative position, a trigger lever pivotally mounted on said support. member and movable into and out of a cooked position, said. trigger lever when in cocked position being, operated by advancement of said work pieces along, said track past said trigger lever toward said nailing position to withdraw said locking member from its operative position thereby permitting said step to move into operative position, and means for withdrawing said stop from. its operative position whereby said locking member is moved into. its operative position and said trigger lever is moved into its cocked, position and. whereby saidv work pieces may be advanced beyond said nailing position after being nailed together,

9. In a machine for registering a pair of work pieces as they are advanced along a track to ,a nailing position in which, .a nailing member is lowered relative to said track to nail the two work pieces together, a stop, a spring for urging said stop into operative position, the advancement of said work pieces along said track being limited by said stop when in operative position to register said work pieces in nailing position relative to said nailing member, a support unember secured to said track, a locking member slidably movable on said support member between operative and withdrawn positions and operative in said operative position to retain said step in withdrawn position, means for urging said looking member into its operative position, and a trigger lever pivotally mounted on said support member and movable ihtoand out of a cockedposition, said trigger clever when cocked position being operated by advancement of said work pieces along said track past said trigger member toward said nailing position to withdraw said locking member from its operative ii sitionilihereby permitting said step to move .into operative position.

10. In a machine for registering a pair of work pieces as they are advanced along .a track to a nailing position in which a nailing member is lowered relative to said track to nail the two work pieces together, a stop, a spring for urging said stop into operative position, the advancement of said work pieces along said track being limited by said-stop when in operative position to register said work pieces in nailing position relative to said nailing member, a support member secured .to said track, a locking member slidably movable on I said support memberbetween operative and withdrawn positions and operative in said "operative position to retain said .stop in withdrawn position, means for urging said locking member into its operative position, a blocking element for limiting the movement of said locking-member' when said stop is in operative position, and means for withdrawing said step from its operative position whereby said locking member is moved into its operative position so that said work pieces may be advanced beyond said nailing position after being nailed together.

11. In a machine for registering a pair of work pieces as they are advanced along a track of a nailing machine to a nailing positionin which a nailing member is lowered relative to said track to nail the two workpieces together, astop adapted for movement relative to said track between operative and withdrawn positions, the advancemerit of said work pieces along said track being limited by said stop whenin operative position to register said work pieces in nailing position relative to said nailing member, means for urging said stop in'to operative position, a locking member movable between operative and withdrawn posi- 12 tions and operative: in said operative position; to". retain, said stop in withdrawn position, a trigger member adapted to,- be. positioned on said track ahead of said nailing; position and movableint and, out. of a cooked position, said trigger mom-:- ber when cocked position being operated bymovement of said work pieces along said track; Past said trigger member toward said nailing po sition to withdraw-r1 said locking, member om its operative position thereby permitting said step to move into operative position, means controlled by downward movement oi said nailing; member for withdrawing said stop from its operative position whereby said work pieces may be advanced beyond said fastening position after being nailed together, and means also controlled by downward movement of said nailing member. for mov ing said locking member into its operative posi. tion and said trigger member into its cocked position.

12,. In a machine for registering a pair of work pieces as they are advanced along a track of a mailing machine to a nailingv position in which a nailing member is lowered relative to said track to nail the two work pieces together, a stop. adapted for movement relative to said track be, tween operative and withdrawn positions, the advancement of said work pieces along said track being limited by said stop, when in operative poo sition to register said work pieces in nailing posia tain relative to said nailing member, means for urging said stop into operative position, a locking member movable between operative and withs drawn positions and operative in said operative position to retain said step in withdrawn position, and a trigger member adapted to be posi! tioned on said track ahead of said nailing position-and movable into and out of a cocked position, said trigger member when in cocked posi tion being operated by advancement of said work pieces along said track past said trigger mam!- ber toward said nailing position to withdraw said locking member from its operative position thereby permitting said stop to move into its operative position.

13. .In a machine for registering a pair of work pieces as they are advanced along a track of a nailing machine to a nailing position in which a nailing member is lowered relative to said track to nail the two work pieces together, a stop for limiting the advancement of said work pieces along said track to register said work pieces in nailing position relative to said nailing member, means controlled by downward movement of said nailing member for withdrawing said stop to permit said work pieces to lee-advanced beyond said nailing position after being nailed together, a locking member movable between operative and withdrawn positions and operative in said operative position to retain said stop in withdrawn position, and means also controlled by downward movement of said nailhig member for moving said locking member into its operative position.

14. In a nailing machine in which work pieces of various dimensions areadvanced along a track to a nailing position in which a nailing member is lowered relative to a track to nail work pieces together, a stop having a connector eccen'trically arranged thereon, and an operating member secured to said connector for moving said stop between operative and withdrawn positions relative to said track, the advancement of said work pieces along said track being limited by said stop when in operative position, said connector being rotatably adjustable relative to said operating 13 member whereby the position to which said work pieces are advanced is adjustable.

15. In a nailing machine in which a pair of work pieces are advanced along a track to a nailing position in which a nailing member is lowered relative to said track to nail the two work pieces together, the combination therewith of: a stop, means for adjusting the position of said stop laterally on said track, said stop being movable relative to said track between operative and withdrawn positions, the advancement of said work pieces along said track being limited by said stop when in operative position to register said Work pieces in nailing position relative to References Cited in the file of this patent UNITED STATES PATENTS Name Date Benson Jan. 2, 1951 Number 

